Well, besides being president of the United States, it's easier to think of differences than to list similarities. The two presidents could hardly have come from more different backgrounds. No one will ever confuse their world views. And the problems confronting the current president would seem, at least on the surface, to have little to do with the conflicts of the 1980s.

But just a glance at some of the recent headlines can quickly send one whirling back to an earlier time.

"U.S., Russia Forge Plan for Arms-Reduction Pact," declared The Wall Street Journal. One could be forgiven for imagining photos of Reagan and Mikhail Gorbachev accompanying the news story.

But the leaders now are Obama and his Russian counterpart, Dmitry Medvedev, who met in London on Wednesday at the gathering of the world's 20 leading economic powers. The two stepped away from finance for a bit to talk about nuclear arms, and the statements that followed the discussions carefully focused on points of agreement, and on the real possibilities of additional progress in the not-too-distant future.

Seems like old times.

We are suddenly back in the era when MTV was the big new thing, when the space shuttle Challenger disaster was seared into our consciousness, when the ball had astonishingly bounced past Bill Buckner at first base.

A quarter of a century later, the U.S. and Russian leaders are again talking about nuclear weapons, about ways to reduce their numbers and make the world a safer place for all of us.

This is a positive development by any measure. The United States and Russia have not had the rosiest of relationships since the end of the Cold War and the collapse of the Soviet Union. If both nations could build some trust and begin the difficult process of lowering the temperature on nuclear arms, we'd really be getting somewhere.